ROS2 Robot Interface

A standalone Python package for communicating with ROS 2 robots through topics. This package is independent of LeRobot and can be used in any ROS 2 environment.

Features

• Subscribe to joint states from ROS 2 topics
• Subscribe to end-effector pose information
• Publish target end-effector poses
• Control gripper position
• Thread-safe data access
• Configurable timeouts and recovery mechanisms

Installation

From Source (Development)

cd ros2_robot_interface
pip install -e .

Usage

Basic Example

from ros2_robot_interface import ROS2RobotInterface, ROS2RobotInterfaceConfig
from geometry_msgs.msg import Pose

# Create configuration
config = ROS2RobotInterfaceConfig(
    joint_states_topic="/joint_states",
    end_effector_pose_topic="/left_current_pose",
    end_effector_target_topic="/left_target",
    joint_names=["joint1", "joint2", "joint3", "joint4", "joint5", "joint6"]
)

# Create and connect interface
interface = ROS2RobotInterface(config)
interface.connect()

# Get joint state
joint_state = interface.get_joint_state()
if joint_state:
    print(f"Joint positions: {joint_state['positions']}")

# Get end-effector pose
pose = interface.get_end_effector_pose()
if pose:
    print(f"End-effector position: ({pose.position.x}, {pose.position.y}, {pose.position.z})")

# Send target pose
target_pose = Pose()
target_pose.position.x = 0.5
target_pose.position.y = 0.0
target_pose.position.z = 0.3
target_pose.orientation.w = 1.0
interface.send_end_effector_target(target_pose)

# Control gripper
interface.send_gripper_command(0.5)  # 50% open

# Disconnect
interface.disconnect()

Configuration Options

from ros2_robot_interface import ROS2RobotInterfaceConfig, ControlType

config = ROS2RobotInterfaceConfig(
    # ROS 2 topics
    joint_states_topic="/joint_states",
    end_effector_pose_topic="/left_current_pose",
    end_effector_target_topic="/left_target",
    
    # Joint names
    joint_names=["joint1", "joint2", "joint3", "joint4", "joint5", "joint6"],
    
    # Gripper configuration
    gripper_enabled=True,
    gripper_joint_name="gripper_joint",
    gripper_command_topic="gripper_joint/position_command",
    gripper_min_position=0.0,
    gripper_max_position=1.0,
    
    # Control parameters
    control_type=ControlType.CARTESIAN_POSE,
    
    # Safety limits
    max_linear_velocity=0.1,  # m/s
    max_angular_velocity=0.5,  # rad/s
    
    # Timeout settings (0 = disabled)
    joint_state_timeout=0.0,  # seconds
    end_effector_pose_timeout=0.0,  # seconds
    
    # ROS 2 namespace
    namespace=""
)

API Reference

ROS2RobotInterface

Main interface class for ROS 2 robot communication.

Methods

• connect() - Connect to ROS 2 and create subscriptions/publishers
• disconnect() - Disconnect and cleanup resources
• get_joint_state() - Get the latest joint state
• get_end_effector_pose() - Get the latest end-effector pose
• send_end_effector_target(pose) - Send target end-effector pose
• send_gripper_command(position) - Send gripper position command
• send_cartesian_velocity(linear, angular) - Send cartesian velocity commands (placeholder)

Properties

• is_connected - Check if the interface is connected

ROS2RobotInterfaceConfig

Configuration dataclass for the interface.

Exceptions

• ROS2InterfaceError - Base exception for ROS 2 interface errors
• ROS2NotConnectedError - Raised when trying to use the interface while not connected
• ROS2AlreadyConnectedError - Raised when trying to connect while already connected

Requirements

• Python >= 3.10
• ROS 2 (tested with Humble and later)
• rclpy
• sensor-msgs
• geometry-msgs
• std-msgs
• numpy

Development

For local development, install in editable mode:

cd ros2_robot_interface
pip install -e .

License

Apache-2.0